For transporting items substantially horizontally, conveyor belts and other mechanisms typically require support structure on both ends of the conveying means. Unfortunately, the support scheme often requires additional floor space and/or complexity of apparatus. Moreover, due to the nature of such supported conveying means, the overall length is generally fixed. The foregoing constraints limit the flexibility of such conveying systems.
While the use of chains provides flexibility, there has been a long sought need to develop a chain that need not be supported on both ends.
U.S. Pat. No. 5,626,013, issued to Schneider, discloses a chain that, when unwound, forms a rigid, linear structure, but which can bend and be wound into a coil onto its take-up reel in the opposite direction. The chain consists of main links and pivot links, alternating with each other. Each link has abutments that restrict movement of its neighboring links in one direction, preventing them from progressing beyond the plane of operation.
A flexible chain and rigid bar combination is disclosed in U.S. Pat. No. 4,885,907, issued to Pappanikolaou. This chain bar requires separate locking mechanisms and a plurality of moving parts, which are susceptible to failure under load.
U.S. Pat. No. 1,004,575, issued to Jones, also addresses the support problem by providing hook prominences. Unfortunately, such prominences tend to catch on fabric and other extraneous objects. Moreover, no provision is made to accommodate the drive sprocket teeth which are normally expected to drive the chain when in use by engaging slots in the chain placed in line at regular intervals.
U.S. Pat. No. 553,650, issued to Kingsland, discloses a lock chain which is rigid only when first laid straight and then compressed end-to-end. Such a procedure is not conducive to modern material handling operations.
It would be advantageous to provide a conveying mechanism, such as a chain, which is self-supporting and locking in all but one direction, so that it may be wound when not in use.
It would also be advantageous to provide a chain that can be extended from a spool and that can remain rigid in one direction for purposes of deploying loads, maintaining the position of same, and/or doing useful work at a distance from the operator.
It would further be advantageous to provide a chain of serially connected, universal links, the chain being movable in one direction, but restricted in movement in the opposite direction.
It would also be advantageous to provide a universal link itself, engageable with neighboring links to form a chain of serially connected, universal links, so that the chain can be movable in one direction, for winding up and storing, but restricted in movement in the opposite direction.